Around 1950, petroleum surpassed coal as the leading energy resource used in the united states. which statement best explains this change?
after 1950, americans started using an increasing amount of renewable energy resources to generate electricity.

after 1950, americans stopped using electricity that was generated by coal-fired power plants.

as more americans started driving automobiles, the consumption of energy derived from petroleum drastically increased.

prior to the late 19th century, wood was the leading energy resource consumed in the united states.

Some plants have reproductive structures that them reproduce using natural forces or animals. how does the reproductive structure shown here ensure the reproductive success of plants?

An uncomfortable feeling in the ears when descending in an airplane is caused by changes in air pressure on the: a. inner ear b. middle ear c. eardrum d. hammer/anvil

18. determine whether each stateme blank space given. ach statement is true (t) or false (f). place your answer in the 8. when a cell is put into an isotonic solution, individual wat put into an isotonic solution, individual water molecules cannot move back and forth across the cell membrane. d. when a cell is put into a hypertonic solution, there is a net movement of water molecules across the cell membrane into the cell. c. when a cell is put into a hypotonic solution, there is a net movement of water molecules across the cell membrane out of the cell. d. the movement of any solvent across a semi-permeable membrane is called osmosis. e. carrier proteins have the ability to change shape and physically move molecules across the cell membrane. f. in facilitated diffusion, the concentration of the molecules to be moved across the cell membrane is higher inside the cell.